Mechanical analysis of moste dam on river Sava

In this paper safety of Moste dam is presented. Three fundamental load cases are taken into account, basic, flood and seismic. Provided with data avaliable, mechanical models are created, using CADAM and TNO Diana. Safety standards for large dams, and different loading types, used to determine a structural safety are presented. Based on output in CADAM and TNO Diana, for this specific case, a deviaton betweeen the two has been evaluated. Based on data gathered during the analysis, functionality (advantages and disadvantages) of both programmes is determined

Short-term streamflow forecasting using the feature-enhanced regression model

Reservoir inflow forecasting is extremely important for the management of a reservoir. In practice, accurate forecasting depends on the feature learning performance. To better address this issue, this paper proposed a feature-enhanced regression model (FER), which combined stack autoencoder (SAE) with long short-term memory (LSTM). This model had two constituents: (1) The SAE was constructed to learn a representation as close as possible to the original inputs. Through deep learning, the enhanced feature could be captured sufficiently. (2) The LSTM was established to simulate the mapping between the enhanced features and the outputs. Under recursive modeling, the patterns of correlation in the short term and dependence in the long term were considered comprehensively. To estimate the performance of the FER model, two historical daily discharge series were investigated, i.e., the Yangtze River in China and the Sava Dolinka River in Slovenia. The proposed model was compared with other machine-learning methods (i.e., the LSTM, SAE-based neural network, and traditional neural network). The results demonstrated that the proposed FER model yields the best forecasting performance in terms of six evaluation criteria. The proposed model integrates the deep learning and recursive modeling, and thus being beneficial to exploring complex features in the reservoir inflow forecasting. Moreover, for smaller catchments with significant torrential characteristics, more data are needed (e.g., at least 20 years) to effectively train the model and to obtain accurate flood-forecasting results

Oblikovanje predstav o slovenskih pokrajinah v izobraževalnem procesu

Shaping the Geographical Imagination of Slovenian Landscapes in EducationThis volume focuses on Slovenian students’ geographical imaginations of Slovenian landscapes and the impact of curricula, syllabuses for selected subjects, and textbooks for them. It proceeds from the premise that photographs play an important role in shaping and maintaining individual and collective conceptions of landscapes. The introduction builds a theoretical framew`rk based on the concepts of landscape, geographical imaginations, and visuality. This is followed by a chapter presenting results of an analysis of twenty-five syllabuses for seventeen primary- and secondary-school subjects referring to shaping landscape imaginations. The third chapter brings results of an analysis of 949 photogrῡphs from fifty primary- and secondary-school textbooks. The fourth chapter presents the results of the analysis of questionnaires completed by 722 students and twenty-seven teachers from seventeen Slovenian primary schools and eight secondary schools. The fifth chapter synthesizes all of the findings.V knjigi so povezana gledišča raziskovalcev in ustvarjalcev, da bi odkrili, kako oblikujejo in soustvarjajo rituale, tako teoretično kakor praktično. Obravnavani so naslednji problemi:stiki med raziskovalci in (po)ustvarjalci in njihovi pogledi, strategijepogajanja in prenos znanja med njimi,ustvarjalci kot domači raziskovalci in vez med uprizoritvami in raziskovalci,ustvarjalci, uprizoritve, raziskovalci in Unescova oznaka kulturne dediščine,kulturne ustanove, izobraževanje ustvarjalcev folklore.Monografija se osredotoča na geografsko zamišljanje učencev in dijakov slovenskih šol slovenskih pokrajin ter na vpliv učnih načrtov in katalogov znanja izbranih predmetov ter učbenikov nanj. Izhajamo iz predpostavke, da imajo fotografije pomembno vlogo pri oblikovanju in ohranjanju individualnih in kolektivnih predstav o pokrajini. Pokrajino razumemo ne le kot preplet dejanskega in videnega, ampak tudi kot rezultat dojemanja in interpretacije. Za oblikovanje predstav je obdobje šolanja z vsemi informacijami, ki jih posreduje, izjemno pomembno

Modeliranje metamaterialov s poenoteno večnivojsko metodo

With monitoring of dynamic properties of dams we can continuously observe the ageing process of the structure, while by vibration monitoring we can estimate the condition of the built-in material. Every structure has unique modal characteristics and its unique vibrational signature that change only in case when the structure\u27s mass, stiffness, or geometry is altered. Therefore, if the structural damage causes a decrease in stiffness, the vibration patterns as well as modal properties of the structure will change. Dams represent an important infrastructure and the ageing of dams and preservation of their structural health is rapidly becoming one of the major challenges of the entire dam engineering community. This research focuses on the analysis of operational loads and their effect on the ageing process of a hydropower dam. Shortly after the construction of the Brežice dam and during the start-up tests of hydro-mechanical equipment, we performed vibration monitoring, using state-of-the-art non-contact measurement techniques in combination with traditional contact technologies. The thesis is divided into two parts. In the first part, the motivation and fundamentals of structural health monitoring, vibration based monitoring, dam surveillance, and Laser Doppler Vibrometry (LDV) are presented, followed by the review of peer literature. Experimental work lies at the core of this research. In the second part of the thesis we present the experimental site, the equipment, the procedure and the numerical models of the powerhouse and its overspilling section. Our research confirmed the susceptibility of the concrete dam structure to the effect of operational loads, which is supported also with numerical results in experimental findings. With the beginning of our work during the construction of the dam we were able to capture the initial reference state of the dam, which will serve as a baseline for future diagnostic work. Furthermore, by adopting a corrective procedure of the LDV output, we are now able to use the LDV during regular operation of the powerhouse, when the instrument is placed inside the structure under observation and excited as well. LDV can be used as part of regular vibration monitoring activities on dams during operation.S spremljanjem dinamičnih lastnosti konstrukcije lahko opazujemo tudi proces staranja objekta, saj lahko preko spremljanja vibracij sklepamo na stanje vgrajenega materiala. Vsak objekt ima zanj značilne modalne lastnosti, ki so posledica njegove zasnove in togosti ter se odražajo v načinu, kako se objekt odzove na mehansko vzbujanje. Če se torej zaradi staranja vgrajenega materiala spremeni njegova togost, se bo posledično spremenil tudi odziv konstrukcije in njegove modalne lastnosti. Staranje pregrad trenutno predstavlja enega glavnih izzivov pregradnega inženirstva. S to raziskavo smo se osredotočili na prepoznavanje in analizo obratovalnih obtežb na konstrukcijo pregrade pretočnega tipa, namenjene za proizvodnjo energije. Stalno prisotna obtežba, ki jo povzroča hidro-mehanska oprema, namreč vpliva na pospešeno staranje betonskih konstrukcij. V okviru raziskave smo izvajali meritve vibracij na pregradi Brežice. Z eksperimentom smo pričeli že v času gradnje. Prvi odziv konstrukcije smo zabeležili kmalu po zaključku glavnine konstrukcijskih del, takrat smo izmerili odziv mlade konstrukcije in zabeležili t.~i. referenčno stanje, ki predstavlja osnovo za vse nadaljnje spremljanje kondicijskega stanja objekta. Pri meritvah smo uporabljali sodobne nekontaktne metode kot tudi tradicionalne kontaktne merilne tehnike. Naloga je razdeljena v dva dela. V prvem delu predstavimo teoretično ozadje spremljanja kondicijskega stanja konstrukcij, meritve vibracij, opazovanja pregrad in laserske vibrometrije. Eksperimentalno delo predstavlja bistvo te naloge. V drugem delu predstavimo eksperiment, opremo, metode dela in izdelana numerična modela. Obratovalna obtežba ima vpliv na pregrado. Vpliv obratovalnih manevrov smo z meritvami med zagonskimi testi zaznali na vseh eksperimentalnih mestih. Precejšnji del naše pozornosti smo usmerili v uporabo laserske vibrometrije v tako zahtevnem okolju, kot je hidroelektrarna med rednim obratovanjem. Vpeljali smo metodologijo, kjer z izvedbo dodatnih meritev na optični merilni napravi izločimo napako zaradi gibanja stojišča, kar omogoča uporabo vibrometra znotraj elektrarne med njenim rednim obratovanjem

Dynamic monitoring as a part of structural health monitoring of dams

Safety of dams and other hydraulic structures is a complex procedure that must consider the individual characteristics of each structure and provide an insight in the structural health at every stage of the structure’s life cycle. Failures of structures permanently or temporarily retaining water may cause large economic damage, environmental disasters, and loss of lives. An engineering design should, therefore, guarantee maximum security of such structures or maximize their reliability not only in ordinary operating conditions but also under extreme hydrological load. By performing structural heath monitoring (SHM), the safety can be optimized, including the performance and life expectancy of a structure by adopting an appropriate methodology to observe the identified failure modes for a selected dam type. To adopt SHM to hydraulic structures it is important to broaden the knowledge and understanding of the ageing processes on hydraulic structures, which can be achieved by laboratory testing and application and development of novel monitoring techniques, e.g., vibration monitoring. In Slovenia, we are increasingly faced with the problem of ageing of dam structures. At the same time, we are also faced with changes in the environment, especially with the variability in time-dependent loads and with new patterns of operation on dams used for hydropower, with several starts and stops of turbines happening on a daily basis. These changes can lead to a decrease in structural and operational safety of dams. In this paper we propose a methodology where the dynamic response of concrete dams is continuously monitored in few locations on the dam using accelerometers, while all significant structural members are measured in discrete time intervals using portable vibrometers. We focused on run-of-the-river dams, which are a common dam type in Slovenia. The pilot case for the system is lower Sava River with a cascade of 5 dams used for hydropower

Structural health monitoring of concrete gravity dams

Staranje vodnih pregrad je eden ključnih izzivov pregradnega inženirstva v Sloveniji kot tudi drugod po svetu. Poleg tega so pregrade izpostavljene spremembam v okolju (podnebne spremembe) in drugim časovno odvisnim vplivom, kot na primer spremembam obratovalnih režimov na pregradah, ki so primarno namenjene hidroenergetski izrabi. Skupek vseh teh sprememb dodatno prispeva k procesu staranja ter k zmanjšanju obratovalne varnosti objektov. Pregrade so zelo pomembni infrastrukturni objekti, ki prinašajo številne koristi kot tudi dodatno tveganje v okolju. V primeru tehničnih okvar in porušitev (delnih ali popolnih) lahko predstavljajo nevarnost za dolvodna območja. Zagotavljanje dobrega kondicijskega stanja starajočih se pregrad trenutno predstavlja enega glavnih izzivov pregradnega inženirstva, saj je povprečna starost slovenskih pregrad že več kot 40 let. S podobnimi izzivi se soočajo tudi drugod po svetu. V prispevku predstavljamo metodologijo za spremljanje kondicijskega stanja betonskih pregrad s spremljanjem vibracij. Metodologija temelji na uporabi nekontaktnih in kontaktnih meritev z beleženjem vibracij na površini konstrukcije. Eksperimentalno delo smo izvajali na pregradi Brežice, ki smo jo začeli spremljati že med gradnjo in nato v prvem letu obratovanja.The ageing of dams is one of the major challenges in specifically Slovenian and generally global dam engineering. Dams are exposed to environmental (climate) changes, as well as time-dependent effects, such as changes in the operating schedules of dams intended primarily for hydroelectric production. These changes can accelerate dams’ ageing and lead to a decrease in their structural and operational safety. Dams are an important part of the infrastructure, as they bring about numerous benefits and at the same time they are also sources of risk. For example, in the event of partial or total failure they pose significant risk to downstream areas. Aging of dams, preserving their functionality, and maintaining their structural health are currently the main challenges of dam engineering. The mean age of Slovenian dams is already over 40 years, although Slovenia is not unique in this situation. In this paper there is presented a novel methodology to monitor structural health of concrete dams, with the use of noncontact and contact measurements through observation of structural vibrations. We present the in-situ experiment on the Brežice dam that began during the dam’s construction and continued into the first year of its operation

On the application of laser vibrometry to perform structural health monitoring in non-stationary conditions of a hydropower dam

This paper presents the first application of the Laser Doppler Vibrometer (LDV) in non-stationary conditions within a hydropower plant powerhouse. The aim of this research is to develop a methodology to include non-contact vibration monitoring as part of structural health monitoring of concrete dams. We have performed in-situ structural vibration measurements on the run-of-the-river Brežice dam in Slovenia during the start-up tests and regular operation. In recent decades, the rapid development of laser measurement technology has provided powerful methods for a variety of measuring tasks. Despite these recent developments, the use of lasers for measuring has been limited to sites provided with stationary conditions. This paper explains the elimination of pseudo-vibration and measurement noise inherent in the non-stationary conditions of the site. Upon removal of the noise, fatigue of the different structural elements of the powerhouse could be identified if significant changes over time are observed in the eigenfrequencies. The use of laser technology is to complement the regular monitoring activities on large dams, since observation and analysis of integrity parameters provide indispensable information for decision making and maintaining good structural health of ageing dams

Terminological dictionary of tax terminology

The Tax Terminology Dictionary is the first Slovenian terminology dictionary with definitions from the field of taxes and contains 972 entries with 993 English and 942 Croatian equivalents. The terms are explained with terminological definitions that represent the conceptual system of the Slovenian tax system. The dictionary was created on the basis of a conceptual approach involving the interdisciplinary participation of field experts and terminologists. In particular, it is aimed at professionals dealing with taxation, protection of taxpayers' rights, or public finance, as well as professionals dealing with tax-related systems such as social work. The dictionary is distributed in XML using the TBX (TermBase eXchange) standard for representing and exchanging information from termbases